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Why do museums limit light levels when displaying paintings?
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Art conservation and restoration
Learn about the restoration of tiles in St. Peter's Basilica, Vatican City.
Museums limit light levels when displaying paintings because exposure to light causes cumulative and irreversible damage to artwork. Prolonged exposure leads to the fading or alteration of original pigments, which can distort an artist’s intended contrasts, depth, and detail.12
Key reasons for these restrictions include:
- Irreversible Decay: Damage caused by light is both cumulative and permanent; once colors fade or change, it is impossible to restore them to their original state.12
- Sensitive Materials: Certain pigments, such as vegetable-based "lakes" or transparent greens like copper resinate, are particularly prone to fading or shifting in color when exposed to light over time.2
- Ultraviolet Radiation: Daylight and fluorescent fixtures contain ultraviolet light, which is especially damaging to organic materials and must be filtered out.12
- Conservation Standards: To balance the need for public viewing with the preservation of the object, conservators typically limit light to the lowest level consistent with adequate visibility—generally around 150 lux (15 foot-candles).2